diff --git a/arch/lmcp/PKGBUILD b/arch/lmcp/PKGBUILD
index 222eb3a7e..a1332e81d 100644
--- a/arch/lmcp/PKGBUILD
+++ b/arch/lmcp/PKGBUILD
@@ -3,15 +3,18 @@
 # Source of truth: git.reauktion.de/marfrit/lmcp
 
 pkgname=lmcp
-pkgver=0.5.4
+pkgver=1.0.0_rc1
 pkgrel=1
 pkgdesc="Lightweight MCP (Model Context Protocol) server in pure Lua"
 arch=('any')
 url="https://git.reauktion.de/marfrit/lmcp"
 license=('MIT')
 depends=('lua' 'lua-socket')
-source=("${pkgname}-${pkgver}.tar.gz::https://git.reauktion.de/marfrit/lmcp/archive/v${pkgver}.tar.gz")
-sha256sums=('af72b8c1d88255456b75d2c53cd5c451a8923417e5498ef31858539397e09caf')
+# Arch pkgver disallows '-'; encode v1.0.0-rc1 upstream tag as 1.0.0_rc1.
+# Translate back for the source URL.
+_tag="v${pkgver//_/-}"
+source=("${pkgname}-${pkgver}.tar.gz::https://git.reauktion.de/marfrit/lmcp/archive/${_tag}.tar.gz")
+sha256sums=('81f9222264371735c196664382460261ef60a259348766bbd6fd2f49ea9d1e7e')
 
 package() {
     cd "${pkgname}"
diff --git a/debian/lmcp/build-deb.sh b/debian/lmcp/build-deb.sh
index 2351d6b1c..55f591740 100755
--- a/debian/lmcp/build-deb.sh
+++ b/debian/lmcp/build-deb.sh
@@ -7,9 +7,13 @@
 # package (Architecture: all, depends on lua + lua-socket).
 set -euo pipefail
 
-PKGVER=0.5.4
+# Debian-conventional pre-release notation: 1.0.0~rc1 sorts BEFORE 1.0.0.
+# Upstream tag is v1.0.0-rc1 (with dash); UPSTREAM_TAG drives the source URL,
+# PKGVER feeds the Debian package version field.
+PKGVER=1.0.0~rc1
+UPSTREAM_TAG=v1.0.0-rc1
 PKGREL=1
-LMCP_TARBALL_SHA256=af72b8c1d88255456b75d2c53cd5c451a8923417e5498ef31858539397e09caf
+LMCP_TARBALL_SHA256=81f9222264371735c196664382460261ef60a259348766bbd6fd2f49ea9d1e7e
 HERE=$(dirname "$(readlink -f "$0")")
 
 # Reproducible build: pin all file mtimes + ar member timestamps to a fixed
@@ -22,7 +26,7 @@ work=$(mktemp -d)
 trap "rm -rf $work" EXIT
 
 cd "$work"
-curl -sSLfo lmcp.tar.gz "https://git.reauktion.de/marfrit/lmcp/archive/v${PKGVER}.tar.gz"
+curl -sSLfo lmcp.tar.gz "https://git.reauktion.de/marfrit/lmcp/archive/${UPSTREAM_TAG}.tar.gz"
 echo "$LMCP_TARBALL_SHA256  lmcp.tar.gz" | sha256sum -c
 tar xzf lmcp.tar.gz
 
diff --git a/debian/lmcp/debian/changelog b/debian/lmcp/debian/changelog
index d29a92712..33bd536b3 100644
--- a/debian/lmcp/debian/changelog
+++ b/debian/lmcp/debian/changelog
@@ -1,3 +1,21 @@
+lmcp (1.0.0~rc1-1) bookworm trixie; urgency=medium
+
+  * Full MCP 2025-06-18 surface (release candidate). Closes 14
+    upstream issues. New primitives: Resources, Prompts, Completion,
+    Logging, Sampling, Roots, fetch, web_search. Protocol: cursor
+    pagination, structuredContent, _meta passthrough, tool annotations
+    (readOnlyHint/destructiveHint/idempotentHint/openWorldHint).
+    Transports: stdio (LMCP_TRANSPORT=stdio) for Claude Desktop / IDE
+    clients; full Streamable HTTP rewrite with select()-based event
+    loop, sessions (Mcp-Session-Id), persistent SSE, server-initiated
+    requests, heartbeat, DELETE.
+  * json.lua: UTF-16 surrogate-pair combination + json.empty_object
+    sentinel for spec-correct {} emission (fixes ping's result:[]
+    bug).
+  * Backwards compatible with all existing sessionless-POST clients.
+
+ -- Markus Fritsche <mfritsche@reauktion.de>  Sun, 17 May 2026 17:25:00 +0000
+
 lmcp (0.5.4-1) bookworm trixie; urgency=medium
 
   * Ship examples/lmcp.service systemd unit template alongside the